Imaging catheters are used in conjunction with guiding catheters to access and map a patient's vascular system. The purpose of the guiding catheter is to more effectively introduce the imaging catheter into the vascular system. The guiding catheter is typically inserted percutaneously into the patient's arterial system through the femoral artery in the groin. With the aid of a guidewire, the guiding catheter is advanced through the patient's vascular system.
Once the guiding catheter is in place, the imaging catheter is introduced into the guiding catheter alongside the guidewire. Such imaging catheters, also known as intravascular ultrasound (IVUS) catheters, have an ultrasonic imaging element attached at the distal end of the catheter for producing cross-sectional images of the vessel. Because the guidewire and imaging catheter are to be employed within the guiding catheter at the same time, the inner diameter of the guiding catheter must be at least as large as the sum of the outer diameters of the guidewire and imaging catheter.
Since prior art imaging catheters have relatively large outer diameters, they are not compatible with smaller guiding catheters, such as 5 French guiding catheters. This incompatibility is a problem since accessing smaller coronary vessels may require the use of a 5 French guiding catheter, and ultrasound imaging would, therefore, be impossible.
It would therefore be desirable to provide an improved imaging catheter having a reduced outer diameter such that the imaging catheter would be compatible with a smaller guiding catheter, such as a 5 French guiding catheter.